1. Field of the Invention
The present invention relates to an image forming apparatus, such as a printer, a copying machine, or a facsimile.
2. Related Background Art
Conventionally, as a method of recording an image on a recording material (for instance, paper or a transparent film), there have been widely known an electrophotographic method, a magnetic recording method, an ink-jet method, and the like.
Among these methods, with the electrophotographic method, the surface of a photosensitive member (photosensitive drum or photosensitive belt) constructed by applying or evaporating an optical semiconductor onto the surface of a conductive drum or belt is evenly charged. Then, a charged latent image (electrostatic latent image) is formed by irradiating the charged surface with light corresponding to image information, a toner image (visualized image) is formed by allowing toner (colored particles) to adhere in accordance with electric lines of force from charges, the toner image is transferred onto a recording material, and an image is formed by fixing the toner image on the surface of the recording material through heating and pressurizing.
Next, with the magnetic recording method, a material for holding magnetism is provided instead of an optical semiconductor, the magnetism holding material is magnetized in accordance with image information, and image formation is performed by allowing magnetic colored particles to be attracted by each magnetized portion.
Finally, with the ink jet recording method, fine particles of ink are directly sprayed on a recording material, thereby forming an image.
In general, each of the electrophotographic method, the magnetic recording method, and the ink-jet method described above has its inherent problem described below.
With the electrophotographic method, image formation is performed through an image forming process including charging, exposure, development, transfer, fixation, and cleaning that are performed in succession, so that the image forming process becomes complicated and the number of process devices is increased accordingly. As a result, the overall size of an image forming apparatus tends to be enlarged.
Also, with the magnetic recording method, it becomes possible to simplify an image forming process, in comparison with the case of the aforementioned electrophotographic method. However, it is required to use magnetic substances as colored particles and the magnetic substances assume darkened colors. As a result, it is difficult to clearly form a color image in colors (yellow, magenta, cyan) other than black.
With the ink jet recording method, there are obtained various advantages. For instance, it is possible to reduce the size of an apparatus and to manufacture the apparatus at low cost. However, the time taken by image formation is long and therefore this method is not suitable for the use in an office or a company in which it is required to print documents in large quantity.
The present invention has been made in view of the above, and an object of the present invention is to provide an image forming apparatus with which it is possible to reduce the overall size of an apparatus.
Another object of the present invention is to provide an image forming apparatus that is suitable for the formation of a clear image and, in particular, suitable for the formation of a color image.
Still another object of the present invention is to provide an image forming apparatus with which it is possible to shorten the time taken by the formation of an image.
Other objects and features of the present invention will become further clear from the detailed description given below in conjunction with the accompanying drawings.